My expertise is the space program and what it should be in the future based on my experience of looking at the transitions that we've made between pre-Sputnik days and getting to the moon.

I know: If you're looking down at Earth, you're looking through an atmosphere that has a bit of haze in many places and not just occasional clouds.

On Apollo 11 in route to the Moon, I observed a light out the window that appeared to be moving alongside us. It was either the rocket we had separated from, or the 4 panels that moved away when we extracted the lander from the rocket and we were nose to nose with the two spacecraft. So in the close vicinity, moving away, were 4 panels. And i feel absolutely convinced that we were looking at the sun reflected off of one of these panels.

The future is about wings and wheels and new forms of space transportation, along with our deep-space ambition to set foot on another world in our solar system: Mars. I firmly believe we will establish permanence on that planet. And in reaching for that goal, we can cultivate commercial development of the moon, the asteroid belt, the Red Planet itself and beyond.

The honor you have given us goes not to us as a crew, but to ... all Americans, who believed, who persevered with us. What Apollo has begun we hope will spread out in many directions, not just in space, but underneath the seas, and in the cities to tell us unforgettably what we will and must do. There are footprints on the moon. Those footprints belong to each and every one of you, to all mankind. They are there because of the blood, sweat, and tears of millions of people. Those footprints are the symbol of true human spirit.

Unless we are able to commit to a permanent growing settlement [on Mars], then I don't think just going there with humans and coming back is worth doing. The expense of planning to come back is like the people who left Europe to come to America and then to turn around and go back to Europe, it really doesn't make any sense at all.

I wrote 'Reaching for the Moon' because I wanted to tell kids that all of us have a moon, a dream, that we can strive for. Even if you don't attain it, you can at least reach for it.